Suction transporting methods and devices are known in the art. In known methods and devices air and water from the environment are normally used as carrying agents. One example of this is a dry-wet vacuum cleaner in which air is used as a carrying agent for transporting solid and liquid particles. Another example is a suction dredge which uses water as a carrying agent for transporting solid particles. A known transporting method and device usually utilizes a source of suction, for example a fan driven by an electric motor, and a transporting line formed as a hollow elongated body. A suction nozzle can be attached to the front end of the transporting line and adapted to take in the carrying agent with the material to be transported. The efficiency of the transportation is determined here primarily by a magnitude of a suction force which is developed at the surface from which the material is taken in by the suction nozzle. The strongest suction force in a particular suction method and device is obtained when the edge of the suction nozzle has a good contact with the surface. However, due to a strong suction force developed by such a nozzle, it sticks to the surface and as a result it becomes very difficult and sometimes impossible to move the nozzle along the surface.
Various means are used to reduce sticking and to achieve better mobility of a suction nozzle. For example, special cuts are made in the edges of the nozzle, or the nozzle is kept elevated above the surface. When the cutting or elevating of the suction nozzle is not desirable, an adjustable slot with a valve body is made in the wall of the transporting line as disclosed, for example, in the U.S. Pat. No. 3,048,876. The above means increases the mobility of the suction nozzle, but at the same time, permanently reduces the suction force at the surface where the material is being taken, and therefore permanently decreases the efficiency of the suction transporting.